This chapter is devoted to the applications of TGD to astrophysics and cosmology.
1. Many-sheeted cosmology
The many-sheeted space-time concept, the new view about the relationship
between inertial and gravitational four-momenta, the basic properties of the
paired cosmic strings, the existence of the limiting temperature, the assumption
about the existence of the vapor phase dominated by cosmic strings, and
quantum criticality imply a rather detailed picture of the cosmic evolution,
which differs from that provided by the standard cosmology in several respects
but has also strong resemblances with inflationary scenario.
It should be made clear that many-sheeted cosmology involves a vulnerable
assumption. It is assumed that single-sheeted space-time surface is enough
to model the cosmology. This need not to be the case. GRT limit of TGD is
obtained by lumping together the sheets of many-sheeted space-time to a piece
of Minkowski space and endowing it with an effective metric, which is sum of
Minkowski metric and deviations of the induced metrics of space-time sheets
from Minkowski metric. Hence the proposed models make sense only if GRT
limits allowing imbedding as a vacuum extremal of Kahler action have special
physical role.....
Keywords: Cosmology, Equivalence Principle, inflation, criticality, quantum
criticality, space-time as surface, many-sheeted space-time, vacuum
extremal, Russian doll cosmology, fractality, zero energy ontology,
causal diamond, Big Bang, Robertson-Walker metric, dark matter,
Planck constant, monopole fluxes, cosmic string, cosmological
magnetic fields.
